The most common type of shatterproof laminate simply comprises a pair of glass sheets sandwiching a synthetic-resin layer that is bonded flatly to the sheets to both sides of it. The sheets are transparent so that the laminate has the external hardness and appearance of a sheet of solid glass. Nonetheless if this laminate is cracked or broken any shards or splinters will remain stuck to the synthetic-resin layer, thereby holding together and creating no safety hazard.
This system has the disadvantage that such a laminate is an extremely good conductor. Thus in applications such as in a greenhouse it is necessary to provide two such laminates spaced apart in order to create an insulating dead-air space. Furthermore, in the event that such a laminate is impacted with considerable force, although a great deal of small dangerous shards are not produced, nonetheless large pieces presenting dangerous jagged edges are created. What is more, as it is necessary for the two glass sheets sandwiching the synthetic-resin layer to have a certain thickness in order to give adequate strength to the finished product, the prior-art laminate is quite heavy per unit of surface area and is relatively expensive. Yet another disadvantage is that if a so-called obscure glass is desired, that is one which lets all the light pass but which multiply refracts the image to break it up, it is necessary to texture the outer surface of the safety glass, thereby creating a unsmooth surface that becomes dirty quite easily.